The United States is urging Turkey to de-escalate tensions over its military operations in Syria and focus on the fight to defeat the Islamic State militants, amid a growing distrust between two NATO allies.

Meanwhile, Turkey is pressing the U.S. to stop its support for Kurdish fighters or risk confronting Turkish forces on the ground in Syria.

U.S.-Turkish relations have suffered another blow, with Ankara and Washington disputing each other’s version of a telephone call Wednesday between the U.S. and Turkish presidents aimed at defusing tensions over Turkish-led forces’ intervention in Syria.

Ankara has rejected Washington’s account of what U.S. President Donald Trump said to his Turkish counterpart, Recep Tayyip Erdogan, denying there was any call by Trump to de-escalate the military operation against the Syrian Kurdish militia the YPG in Syria’s Afrin enclave.

But Washington said it stands by Trump's "firm" and "tough" stand during his phone call with Erdogan.

"We stand by the president’s assertion of cautioning Turkey about the escalation of tensions in Afrin area," said State Department spokesperson Heather Nauert on Thursday.

"We certainly hope they [Turkish leaders] will listen," said Nauert, "that would be a good thing."

The White House reported Trump said the Turkish operation "risks undercutting our shared goals in Syria," and "urged Turkey to de-escalate, limit its military actions, and avoid civilian casualties and increases to displaced persons and refugees."

Turkey's President Recep Tayyip Erdogan gestures to supporters of his ruling Justice and Development Party at a rally in Bingol, Turkey, Jan. 13, 2018.

The dispute over the contents of the telephone call is exacerbating a lack of trust between the two NATO allies.

The United States has supported the YPG militia in the war against Islamic State. Ankara considers the YPG a terrorist organization linked to a Kurdish insurgency inside Turkey.

In Ankara, a governmental official said anyone supporting the YPG militia will become "a target."

"The United States needs to review its soldiers and elements giving support to terrorists on the ground in such a way as to avoid a confrontation with Turkey," said Turkey’s Deputy Prime Minister Bekir Bozdag on Thursday.

Yildirim said, "This country we call a NATO ally is in cahoots with terror organizations." He called it a grave and very painful situation, accusing the United States of working with terrorist organizations. He said Turkey will never accept this.

The prime minister’s latest comment is fueling expectations Ankara will carry out its threat to expand its operation against the Syrian Kurdish militia to Manbij. U.S. forces are deployed in the Syrian town with the YPG militia.

At the Pentagon, a spokesperson said the U.S. has not seen any indication that Turkish forces are moving toward Manbij on Thursday.

Ankara’s lack of trust in Washington is now becoming a major obstacle to resolving the Syria crisis.

U.S. Secretary of State Rex Tillerson, left, meets with Turkish Foreign Minister Mevlut Cavusoglu in Istanbul, Turkey, July 9, 2017.

Turkish Foreign Minister Mevlut Cavusoglu ruled out a proposal he said was made by U.S. Secretary of State Rex Tillerson to create a 30-kilometer security zone inside Syria to protect Turkey's southern border. Cavusoglu said until trust is restored, no deal can be made.

But Tillerson later denied he made such proposal.

"We discussed a number of possible options, but we didn’t propose anything," said Tillerson on Thursday at Davos when asked if he proposed a safe zone inside Syria to Cavusoglu when the two top diplomats met one day earlier in Paris.

Ankara is at odds with Washington on issues besides Syria.

Turkey is calling for the extradition of U.S.-based Turkish cleric Fethullah Gulen, who Ankara blames for a failed coup in 2016. The cleric, who lives in self-imposed exile in the state of Pennsylvania, denies the accusation.

Meanwhile, U.S. authorities are reportedly in the process of considering a massive fine against the Turkish state-owned lender Halkbank in connection with Iran sanctions busting, following a conviction in New York of one of its senior executives.

Erdogan has alleged the executive's conviction in the federal case is the latest attempt by the FBI and CIA to unseat him.